Low back pain causes a high burden of suffering (symptoms and disability) and heavy costs to society related to medical care, lost work and compensation. There is little consensus about the effectiveness of current diagnostic tests and treatments. Health services for back pain vary substantially across small areas, suggesting that some of the care may lack effectiveness or efficiency. We propose a program of research on the outpatient medical care of low back pain. The studies will track the problem from the onset of symptoms in the community and patients' decisions to seek care for low back pain, through clinical decisions about diagnosis and treatment of patients in office practices. The main focus will be on outcomes of care (in patients' terms) costs, and factors that affect both. The studies will be conducted in the state of North Carolina. This application is a resubmission of an application from 3/90, which was approved but not funded. We have taken reviewers' comments into consideration. This proposal concentrates on outpatient diagnosis and treatment. We propose two related studies, and describe in detail the methods that will be used. The research program will conduct two studies. A telephone survey of a random sample of N.C. households will describe the incidence of low back pain, the rate at which individuals seek care from practitioners for low back pain, and the type of practitioner they seek care from (primary care physician, surgical specialist, chiropractor). The second study will be a cohort study of patients presenting to practitioners offices with acute low back pain. Twenty five practitioners will participate in each of six strata: urban primary care physicians, rural primary care physicians, neurosurgeons/orthopedic surgeons, urban chiropractors, rural chiropractors, and primary care physicians in a prepaid setting. Ten patients presenting to practitioners with acute low back pain will be followed by telephone periodically for six months, assessing time to recovery, diagnostic tests used, and treatments utilized. We plan to then determine which factors contribute most to recovery from acute back pain: treatment mode, diagnostic test usage, type of practitioner seen, or social factors such as the status of back pain as a compensable injury. The assessment team for this project will include a multidisciplinary group of investigators with experience in research of back pain, health services research, and primary care research. The North Carolina team will consult with the Back Pain Outcomes Assessment Team (BOAT) at the University of Washington. Collaboration will take place in the design of telephone instruments and cost-effectiveness analysis of diagnostic and therapeutic strategies.